Shimano's new 9100 series Dura-Ace drivetrain outperforms its predecessor in nearly every aspect, but in such small ways that they're easy to miss.
What is it
Shimano's new 9100 series Dura-Ace groupset improves upon its previous mechanical shift, hydraulic brake groups with better ergonomics, smoother lever action, and better looks. While certainly expensive, Shimano's top tier groupset continues to deliver top notch performance, too.
- Shifting improved over previous generation
- Improved shift lever ergonomics
- 11-30T cassette and chain quick link welcomed
- Nothing hotter than black on black
- New brake pads not compatible with Shimano mountain bike brakes
Any new generation of a drivetrain from Campagnolo, Shimano, or SRAM merits a thorough review. RoadBikeReview got its hands on one of the first Shimano Dura-Ace 9100 series groupsets with mechanical shifting and hydraulic brakes. We've used it consistently for a couple months now and the group continues to impress. But then again, Dura-Ace needs to do so. As the pinnacle of road technology from Shimano, it is among the groups that create the benchmark.
While some pundits expected the new group to have 12 speeds at the rear, Shimano stuck with 11. But don't mistake Dura-Ace 9100 as a mild update. It is a complete overhaul with each component receiving a new look and re-engineered function. And keeping it 11-speed means that current Shimano or SRAM riders don't need new wheels.
The flat mount brakes certainly fit the aesthetic or road and gravel bikes. The black cooling fins on the RT900 rotor are visually distinctive.
In a departure from the black and polished 9000 series components, the new Dura-Ace is entirely black. Alongside the matte paint phenomenon in which the cycling world finds itself, the new Dura-Ace fits in nicely. It looks sharp but sets off flashy frame and fork paint in a big way.
The new 9100 cranks save a few grams over previous generations, but also bring a new chainring profile that is designed for better performance on disc brake-equipped bikes.
Stiffer and lighter. All the normal buzzwords are here. The crank may be a touch stiffer, but it would take a science experiment to quantify it. Weight only dropped by 7 grams according to Shimano. The bigger news is that Shimano tweaked the chainring profile to work better with disc brake bikes and their wider rear triangles. The new profile accommodates chainstays as short as 410mm. This may sound like a minor detail, but it's all part of the constant evolution of road bikes. That Shimano did this without increased Q factor is significant.
Also worthy of mention here is Shimano's new power meter. While we didn't have a chance to test one, on paper it looks impressive. For now it's a Dura-Ace option that we'll see on pro team bikes only.
The mechanical shift/hydraulic brake levers are tidy enough that they could be easily mistaken for a rim brake version. The new lever's ergonomics are a big improvement over Shimano's RS685 levers.
Across the entire generation of new Dura-Ace shifters (mechanic shift/mechanical brake, mechanic shift/hydraulic brake, Di2 shift/mechanical brake, and Di2 shift/hydraulic brake) lever size is smaller. There is still a sizeable bulb at the top of the lever that houses the shift mechanism, but the circumference of the main lever body is decreased. We measured the 9100 hydraulic lever at 15cm near the handlebar. Shimano's previous mechanical shift/hydro brake lever (RS685) measures 15.6cm at the same location.
The shape, in cross-section, of the new lever is also more ergonomic. It remains flattish on top, but extends further down on the outside of the lever than it does on the inside. The taller outside creates a nice grip shape. The R685 cross-section is squared in comparison.
Also improving the feel of the shift lever are far better hoods than were seen on RS685. The new hoods have nice texturing and don't rotate on the lever body like some RS685 levers did.
The smaller shift paddle, the one used to shift to a smaller chainring or cog, is larger and more concave than before and receives a nice, rubbery texture. Lever throw may have decreased a touch, but more obvious is the improved shift action with a more distinct click.
Shimano shifting has been excellent for some time, but with 9100 the Japanese component giant managed to polish its action further. Front shifts, under virtually all circumstances, are silky smooth, and rear shifts, even on the mechanical drivetrain, happen almost as quickly as your brain registers the need for one.
The new Dura-Ace rear derailleur borrows its low-profile design from mountain bike derailleurs. It smooths aerodynamics and protects the mechanism in case of a crash.
The new 9100 rear derailleur illustrates perhaps the biggest departure from its predecessor. The shape borrows from Shimano's mountain bike line, with a low-profile design and a longer pulley cage. The slimmer profile reduces the likelihood of damage in a crash. The longer pulley cage also accommodates the new 11-30T cassette (discussed below). Shimano also made passing comments about the new design being more effective on bumpy roads, with it less likely to bounce out of gear momentarily in the rough stuff, good news for mixed surface or gravel riders.
Gone from the front derailleur is the long cable anchor arm of the 9000 series. This is good news as the long arm interfered with some bikes with large tires and short chainstays. The new version is lower profile while reducing the amount of force required for a shift to the big chainring. It also includes an integrated cable tensioner, eliminating the need for an inline barrel adjuster. On the road the front shift to the large chainring feels more natural, with a flatter arc of force required than before, while the 9000 generation had an obvious peak in required shifter input.
Gone is the long arm of the 9000 series front derailleur. The new toggle design provides smoother action, increased tire clearance, and an integrated cable tension adjuster.
New for the 9100 series is an 11-30T cassette. It's a welcome site for those of us who like to spin up climbs or take on steeper pitches. Lovers of 11-25, 11-28, 12-25, and 12-28T will still be happy. All are offered in the new lineup.
Shimano has gone back and forth on the asymmetric chain design, using it in some generations and doing without for others. The 9100 group gets an asymmetric chain, the HG901-11, which features Shimano's Sil-Tec friction and noise reducing treatment on the rollers and plates. The new chain uses hollow pins to keep weight to a Shimano listed 247 grams for 114 links.
A welcome sight for mechanics everywhere is Shimano's CN900-11 quick link. Yes, it's true, the days of pressing in chain-specific pins are gone!
For the first time, Shimano has assigned its Dura-Ace brand to a disc brake. Previous road disc brakes were non-series (think RS685 or R785). Shimano said at the release of its first hydraulic road disc brakes that it wanted time to develop a product befitting the name of its top-tier group. With 9100, they obviously felt ready and I have to say that braking performance is fantastic. But I personally can't distinguish a difference in stopping power or modulation from previous road disc brakes from Shimano. The biggest differences are in the brake lever ergonomics and lever action.
Where RS685 and R785 levers had a distinctive ramp in the action (much like the front shifting action), the Dura-Ace hydraulic levers smooth that action out. Your hand encounters less resistance to pulling the lever. This is welcome. Even more welcome is the decreased lever throw.
Comparing apples and oranges for a moment, Shimano's Di2 hydraulic levers, R785, had a very long throw even with a perfect bleed. This was troublesome for riders with smaller hands. If they adjusted the lever to fit their hand it could bottom out on the bar before fully engaging. The new levers have a shorter lever throw and a much smoother movement through that range.
Braking on the new Dura-Ace is excellent with lever feel smoothed across its throw. The modulation and stopping power inspire confidence.
The new Flat Mount brakes, like all from Shimano, use non-toxic mineral oil. The new 9100 brakes are also one-way bleed, making installation and maintenance easier. The new levers do require a new bleed fitting, but the plastic tool is included with the brakes if purchased separately. Shops should also receive them with complete bikes.
Somewhat annoyingly, the new flat mount brakes use a different brake pad shape. While the profile of the pad material appears similar to past brakes, the finned section has a new shape. This means you can't have spare pads for your Shimano mountain bike brakes on hand and also use them on your drop bar bike.
The most distinctive part of the 9100 series disc brakes is the new RT900 rotors and their extended cooling fins. On the Dura-Ace version, the center portion is painted black and it lends a motorsport look to the complete bike.
Should you buy it?
That depends. If you are already aboard Shimano's 9000 group then perhaps not. The improvements are real, but they consist of a long list of small evolutions, not a watershed of innovation.
On the other hand, if you're considering disc brakes for the first time, then go for it. These are the most refined drop bar disc brakes I've used. That the stopping prowess of 9100 is backed by the slickest road shifting in Shimano history is pretty hard to pass up.
Ultimately, Dura-Ace will continue to be two things, expensive and excellent. For some, the blacked out look of the new Dura-Ace is enough to pull out a credit card. The improved lever ergonomics, shift and braking action, wider cassette range, chain quick link, and slightly lighter weight all add up to a phenomenal road groupset. If you do decide to pull the trigger on 9100, you'll be happy with your purchase.
- ST-R9120 levers and BR-R9170 brakes: $1180
- RT900 rotors: $85 each
- FCR9100 crank: $600
- BBR9100 bottom bracket: $40
- RDR9100 rear derailleur: $230
- FDR9100 front derailleur: $120
- CSR9100 11-30T cassette: $270
- CN-HG900-11 chain: $50
Rating: 4.5 out of 5
Price: $2660 for total mechanical shift/hydraulic brake group
More Info: bike.shimano.com